Whole blood samples are often fractionated to separate red blood cells, platelets, and other cellular materials from the plasma and other fluid components of the whole blood. A selected fraction, typically red blood cells or cellular materials, can be selectively withdrawn from the fractionated whole blood sample for use in certain medical applications. The isolated cellular material is often further processed by adding one or more wash fluids to the isolated cellular materials to remove any plasma or other undesirable fluids or materials clinging to or intermixed with the desired cellular material. The resulting wash solution comprising cellular material within the wash fluids is often fractionated again to separate and isolate the cellular material from the wash fluids.
For certain medical applications, the cellular materials must often be washed multiple times to cleanse the cellular material to certain predetermined standards. However, each wash cycle requires the addition of new wash fluids, fractionation of the wash solution, and isolation of the cellular materials from the wash fluids, which is time-consuming and is often labor intensive. Also, as the wash solution is typically centrifuged to fractionate the wash solution, separate containers must be connected to add or withdraw wash solution from the centrifuge rotor before being disconnected to permit rotation of the centrifuge rotor for fractionation. The repeated connection and disconnection of separate containers can increase the risk of contamination or degradation of cellular material within the centrifuge rotor.